Comfort with Improved Handling
 

Hey guys, so I'm out here building what I want my turbo Miata to be:

I want my Miata to be the equivalent of a 2009 Porsche Cayman S in terms of comfort and performance. The MK turbo kit boosts power a good bit, so that's good to go there. Time to tackle suspension and brakes.

A) I don't want to go with the harsher ride of coilovers, but I also don't want the wallowy softness of stock suspension. Some of the roads around Florida are marginally better than that of a third world country, and half the highway is under construction at any given time, so I want something that will absorb the bumps when I go over them.

B) However, when I take it to the track, I want to be able to drive up and with minimal adjustments go out there and crush it. I think stiffer suspensions really aren't necessary for good track handling anyway, you still want some degree of body roll and weight transfer. These aren't Formula 1 cars.

I will not be lowering the car beyond 1 inch. I don't want to scrape on leaves.


So realistically I am probably looking at some spring/shock combo. Maybe H&R and Bilstein? Tein and Tokico?

Xida GS.
/thread

550/350 spring rates are probably going to be extremely stiff and harsh, there's no way they'll be livable on the poorly maintained dirt road known as I-95 or State Road 826.

$1700+ is also wildly out of budget. I should have stated that, perhaps no more than $1k for all components.

Assembled a spreadsheet of different springs and dampers

So I'm kinda looking at the Tein S-Tech springs, rates of 224/168, which are slightly higher than that of MSM springs at 215/158. Combo this with Bilstein B8 dampers and I think this could be good and comfortable. What do you guys think?

I was considering FM springs, but at 318/233, I've read that they tend to be on the harsher side.

Racing Beat springs are 195/145, so that might be a bit too soft, even softer than MSM.

Realistically a custom bilstein setup is going to be the closest thing for what you want that is also within budget.

The Xida GS is the perfect solution for what you want though, I have the 550/350 springs and it rides better than stock. (Rural Canadian backroads that get layered in salt for half the year.)
They're also very nice on track.

If you say so, I'd love to try them out for myself. There's no way 550/350 can be more comfortable than 162/118. If it wasn't for my blown shocks, my Miata would probably glide over bumps in the road.

I used to own a 240SX with BC coils, harsh ride. I then had another 240SX with Fortune Auto coils, better but still pretty stiff.

I'm not yet an old man, I just want to find the best compromise between handling and comfort without going broke.

Not an apples to apples comparison, but I'm running (IIRC) 550/350 on my NA, on Pro-Tech shocks with custom valving to match the springs - so a similar-ish setup to the Xidas.

The ride was a massive improvement compared to stock (on NA bilsteins) - sure if you hit a big pothole you can feel it, but the car remains composed. UK roads are pretty much as bad as US ones, and it's certainly not too bad to daily drive, and has worked well enough on the track when I've taken it there.

We also have a 987 Boxster-S in the family, in terms of suspension only - with the suspension on normal mode (not sport) it's not that much different in terms of firmness (although the rest of the car is much more refined).

I suppose what I'm trying to say is spring rates are only half of the story - how the shock is valved is the other half, if they are setup to work together then you are going to get good results. From everything I've read about the Xida range, they are properly thought out in terms of rates and valving so I don't think they are going to be as harsh as you think.

When I removed my old suspension they only had 45,000 miles on them, so it's not like it went from blown shocks to properly functioning shocks.

When a spring is too soft it rides lower in the stroke and creates a harsher ride as it blows through the available travel and begins to get into the stiff part of the spring or even the bump stop. Keeping the suspension higher in its range of motion means it works as it should.

On track with stock suspension the car would be locked onto the bump stops with the inside front wheel in the air, no bump absorption at that point.

Hmm yeah that's right. Conversely, having a spring that's a bit softer means that at rest it's compressed a bit, and when you go into a dip then the softer spring can extend to fill the gap between the tire and the dip. Your scenario covers comfort with compression, this scenario covers comfort with rebound.

I've actually experienced situations with my 240s where riding over a dip in the highway would actually cause the car to "fall" into the dip because there wasn't enough suspension travel to cover the distance. It jiggles all your internal organs and you feel awful when you get out of the car. Not fun.

Judging from the responses in this thread, I'd actually really love to try out the Xida coils, y'all are raving about them. Unfortunately they're vastly (bigly?) out of budget for me, so I can't consider them for this build. The GS coils would cost almost as much as I paid for the entire car.

I get what you are saying however you are on a turbo miata forum, most of us have spent much more on mods than the initial cost of the car. You can't really use how much you paid for the car as a metric for what you should pay for mods. I am using Koni/GC for the time being. With 350/250lb spring rates I find them to be acceptable and we have awful roads.

The stock Miata rates are designed to allow contact with the tall stock bump stops as soon as you start cornering. Settling with age causes this contact to occur more easily.

The car needs enough spring rate and travel to keep it off the stops in steady state cornering with your chosen tire. Stickier tires require more spring or more travel to achieve this. Stock rates were designed to get firmly on the stops with skinny all-seasons in a corner.

A 200 lb per inch spring will support 200lbs of weight with 1 inch of available travel but will carry 400lbs with 2 inches of available travel. 400lb per inch springs can carry 400lbs off the stops with 1 inch of travel. Lower cars need more spring and/or travel to not crash into the stops.

Proper digressive valving is important for ride quality, moreso than spring rate. Some "performance" shocks have way too much high speed damping, causing a rough, jittery ride over damaged or uneven pavement. Some shocks have too little low speed damping, making the ride floaty and uncontrolled. The proper digressive damping curve should inspire confidence and stability on smooth surfaces at speed but relax that control when irregularities are encountered so the tire can maintain surface contact and not unsettle the car or lose cornering adhesion. Xidas were optimized for the best of both with modern sticky R-compounds which is why they were recommended.

For a budget setup with a plush, controlled ride and wider than stock street tires, and lower than stock ride height (5.25-5.75ish pinch weld), I would reccomend the Bilsteins with 400/300 rates, cut down or replaced bump stops, and rear extended tophats. I had a similar setup and was amazed how much more comfortable than stock it rode. I was also concerned about the higher spring rates and didn't believe it could possibly ride anything but worse. I was wrong. It was much, much better.

TL;DR- Shock valving and travel contributes more to ride quality than spring rates, within reason.

FWIW, spring rates on Xidas don't actually feel as high as they may seem. My Xida Race 700/400 setup is way more comfortable and compliant than my previous FM stage 1 with 318/233 springs.

You're not going to get Porsche quality with Teins

Sixshooter and others have nailed it; I went thru the same debate with my Lotus Elise: horrible street ride with stock, lower rate(Bilstien coilovers) springs, almost as if it had wooden tires. Reading about the P-Zero coilovers the UK guy's were running made them sound great, but the spring rates were up quite a bit over stock Bilstien's, but I went with them and could not believe how it transformed the car; MUCH more comfortable ride, much better, controlled in a track situation. Probably the best $$ I'v spent on the car.

What you interpret as a rough ride on sub-200 rates is actually contact with the stops.

Hmm yeah, I've only been looking at spring rates without looking at damping as well. I wonder what exists within my budget of say, $700-800 that accomplishes what I want.

I know I shouldn't look at the price of the item relative to what I paid for the car to judge its value, but I also don't have $1700 to blow all at once. I don't even have the $800 to spend right now, this is a purchase I'm planning for the future.

So I take it that this setup might not be ideal for my purpose? It is within budget, so that's nice.
https://cimg1.ibsrv.net/gimg/www.mia...e659002ad5.jpg

I didn’t see anywhere what model/year your car is or really what your end goal is other then some nebulous comparison to a 2009 Porsche. If you’ll never see a track or an auto-x event just go out and buy the FM V-MAXX with the sway bars as a package. Install and drive... you could do worse.

2002 Miata, and yes I will be tracking the car on occasion

You could build yourself a set of Bilstein based 2.5" coilovers for close to the low end of your budget depending on how you source and shop for parts. Then just buy the Supermiata sway bar kit and install at the same time. You'll be just over a grand.

The thread has gotten a bit off topic at times but still usable: The Better Bilstein Ebay Coilover Thread

Tein springs suck. They are way too soft and will probably ride worse than 400/300 springs due to the bumpstop contact. Also they have issues with rake that can't be fixed due to the non-adjustable spring perches.

My bilsteins were running springrates similar to those and they rode like shit due to hitting the bumpstops (nonexistent in the back). Twice the springrate rides like butter.

I am running stock swaybars and they are fine.

Get B8s/Allstar Sleeves/Cut Integra Bumpstops/QA1 springs, cut the bumpstops to 30-35mm, cut the sleeves to 3" long from 5" with a hacksaw, profit

I will also say to save up more and go with the Xida GS. Yes they are expensive, Yes they are worth every penny. I have been through over a dozen different suspensions over the past decade plus. If I could go back to 2005 I would tell myself 2 things.

1. Stick with 220whp and a stock motor.
2. Save up and buy Xida's to start with and never worry about suspension again.

@OP, You mentioned I95 and 826. Dunno how far from you are but I am in Miami and I run Bilstein shocks with 550/350 rates. If you want to feel how that feels, let me know.

Yeah that would be awesome, I'll send you a PM and we can meet up

Just realized something. The Tein springs may be similar in rate to the MSM springs, but they also sit lower than the MSM springs. This would probably cause them to bottom out quicker, meaning I would be riding the bumpstops more than I should be. Stock MSM springs probably have alot more travel.

Actually, what do you guys think about swapping to MSM bilsteins and springs? Would that achieve the result I want?

Gonna look into the DIY coilover kit as well.

MSM Bilsteins have dampening issues, the stock springs are still too soft. MSM Bilsteins with Flying Miata Springs and FM Bumpstops is actually pretty good, I have rode in + driven and helped install a setup like that. Not as good as a Yellow Bilstein setup w/ coilover sleeves and stiffer springs, but still comfortable and stiff enough. If you can pick up a set of used MSM Bilsteins for 100-150$ it may be worth it to do that instead. Ride height will be similar to stock.

I've decided to go with the DIY Bilstein B8 coilovers. Seems to be the best compromise between budget, performance, and customization so that I can play with spring rates and find what suits me best.

Should I also look at KONI Yellows? The adjustable damping might be useful as well.

1) Koni yellows suck so badly it's ridiculous.
2) They are not adjustable.
3) If they were better we'd be reccomending them.

First, to clarify a few of your misconceptions;

- The OEM shocks are coilovers
- Aftermarket coilovers do not necessarily mean a bad ride. Cheap coilovers can be harsh. High end coilovers setup for maximum competition performance might still be too firm for street use but are not likely to be harsh.
- Aftermarket coilovers do not necessarily mean needing to lower the car too much
- "Crushing" it on track and best possible street ride quality are going to conflict. Choosing something in between means it excels at nothing. We prefer to nail one use perfectly, and still be pretty good at the other. We generally push a softer setup when it's a dual use car. This way 95% of the time you drive it (on street) the car is amazing and still fun and responsive on track. Just don't expect the same setup we would do for the same weight Miata that's focused on lowest possible lap times. A softer setup means being a smoother driver, more patient in transitions and being OK with something less that the grippiest tire. A setup that's perfect for 225/45R15 Hoosiers on 9's is going to feel like crap on 205/50R15 Conti ECS on 8's.

So we need more info on your build to dial it in. Apologies if it's elsewhere in the thread:

Total weight w/ driver
Tire size and model used for track + wheel offset
Tire size and model used for street + wheel offset
If using aftermarket sway bars, what model/size

My two recommendations would be our Xida GS (550/350) / XL (custom rates) / Xida ACE (semi active, custom rates) or FM Fox.
Everything else will be too short, have inadequate damping, or both.

The B8/S-Tech combo you listed is my standard recommendation for "I want more but adjustable shocks aren't in the budget". As good as it gets below $1200 IMO.

You know what, I was thinking of KYB adjustable shocks, I think the AGX model. Either way, the Bilstein B8's standard damping seems to be adequate for a wide variety of spring rates, so I'll just stick to that.


Nice, lots of good info in this post, thank you! Really clarifies alot of misconceptions I had about the Miata factory suspension.

I'm considering going with the B8s and building coilovers, the price difference isn't that much between them and I'll have the advantage of being able to pick and choose spring rates.

B8s + S-Techs end up being around $600, but for about $800 I may be able to build a set of coils.

Made this spreadsheet. Looks pretty complete huh?

https://cimg1.ibsrv.net/gimg/www.mia...8661f4cb9b.png

Also, to answer your other questions:

Total weight w/ driver: 2640 lbs
Tire Size (will use same tires for track and street): Likely going to be Federal RS-R or Hankook RS4
If using aftermarket sway bars, what model/size: Likely going to be Eibach, 26mm

I don't really care about having the absolute best lap times, I understand I'm going to compromise a bit on this. I just want to show up to the track with minimal preparation and have fun. In the past I used to do the whole "swap brake pads, tires, change suspension setup" before every track day, and it's just a pain in the butt. I always liked how guys in Porsches would show up and wouldn't do a thing to their car and just have fun. I want to do that.

I've also got this going on, if it helps. It's a spreadsheet I put together.

https://cimg3.ibsrv.net/gimg/www.mia...125bd9978f.png

Indeed. Emilio references this but it's an important distinction: Firm =/= harsh. High spring rates will be firm and follow the road closely, but with proper valving in the dampers, won't be harsh. I am not kidding you one tiny bit that my car on 700/400 pound springs (and Xidas, of course) is far, far less harsh than any stock suspension Miata I've driven, even fresh super low mile ones. Yes, it's more firm, the car follows undulations in the road, but you get on an expansion jointy freeway and slam a bridge joint at 80 mph and it just completely soaks it up. Driving it back to back with our GT350 (stock adaptive dampers and ford performance springs), my Miata is less harsh.

You say you want it to ride like a Porsche but won't spend more than $1000... gonna be tough. Best bet in that price range is definitely the Bilstein direction you're heading, but you're still going to be sacrificing some ride quality and some on-track performance compared to the Xida. If you *actually* want suspension that's going to ride like buttah and still crush it on track, you're going to need to spend some more money.

Basically this is what's happening

https://cimg9.ibsrv.net/gimg/www.mia...d9fab55938.jpg

I don't need the Iron Throne, I'd be okay with the Pool Noodle Throne as long as it's decently comfortable and good handling.

Bilsteins are your noodle.

Awesome. That list I have up above, looks pretty complete? Am I missing anything?

Dunno, I bought Xidas (before I started working here).

Don't be afraid to up the springrates to the 450/300 range, that's what I am running. I would classify them as firm but comfortable. 550/400 gets near the limits of stock-valving B8s, I personally think 300/225 is a bit soft but I haven't really experienced those rates.

You left out the extended top hats for the rear which will be even more needed since you went with such sloppy spring rates.

Well, I guess what's cool is that experimenting with different setups should be easy. Cool that the B8 works with such a wide range.

Any recommendations? I've seen Maruhas and stuff like that posted.

There's a bunch of them. Pick one you like. Maruha, ISC racing, I can't remember who else. Some are prettier than others but they will all do the job.

[QUOTE=dsamani;1537046]Hey guys, so I'm out here building what I want my turbo Miata to be:

I want my Miata to be the equivalent of a 2009 Porsche Cayman S in terms of comfort and performance. The MK turbo kit boosts power a good bit, so that's good to go there. Time to tackle suspension and brakes.

It never will be. Apples and oranges.

A) I don't want to go with the harsher ride of coilovers, but I also don't want the wallowy softness of stock suspension. Some of the roads around Florida are marginally better than that of a third world country, and half the highway is under construction at any given time, so I want something that will absorb the bumps when I go over them.

Stay off the bumpstops.

B) However, when I take it to the track, I want to be able to drive up and with minimal adjustments go out there and crush it. I think stiffer suspensions really aren't necessary for good track handling anyway, you still want some degree of body roll and weight transfer. These aren't Formula 1 cars.

What track and what skill level? If you are talking Sebring at an advanced pace you will need very stiff springs to stay off the stops. If you are slow on hard tires at PBIR, not such an issue?

I will not be lowering the car beyond 1 inch. I don't want to scrape on leaves.

Again at Sebring you need a bunch of travel. Slammed is stupid.

Sounds like you want and need XIDA but don't want to spend crush it at the track or Cayman money
QUOTE]

I'm pretty sure Xida's are cheaper than OEM Cayman S shocks, lol. They are a definite bargain for what you get.

What is it exactly about the Xida coilovers that make them so ideal? Spring rate? Damping? I see that they have extended top hats from the factory.

It's all about the valving. Xidas have high quality shocks with ideal valving specifically for miatas.

Xidas have regular nb top hats. Or the more expensive custom hats.

I run bc racing br coilovers, the street ride is great and they handle well at the track. It's a great option at the $1k price point.

A good setup is not just about the valving - for a setup to be good it's the combo of valving in conjunction with spring rates, and suspension travel.

Alright, anybody got a shock dyno of some Xida coilovers ask well as dyno sheets of other coilovers?

You want me to Google that for you or something?

You can try to find all the dyno sheets you want. There is nothing sub $1k that compares to the xidas.

You want sporty reasonable comfy ride? Bilsteins extended rear top hats, and 400/250 ish springs

Comfort and good track performance? Xida gs

Less comfort and excellent track? Xida race

Have small budget? Raceland or tein. Will get you low, shit ride and performance.

BC makes good midrange coilovers, as well as FEAL, and MEISTER. All around $1000-1300

This is most of the popular miata suspension options.

I personally only have experience with BC and I like them.

Cant wait to step out from teins into a xida or penske setup. Teins get the job done but are nowhere near great.

Xidas or nothing

/Thread


Seriously, they are EXACTLY what you want. They were custom made for your exact car to ride exactly the way you have described. Save up some more and DO IT.

I'm on some Racelands installed by the PO (ugh) but they aren't terrible feeling. I've been in a Miata with stock suspension and they feel better than that. But I wouldn't call them pleasant either. My next major purchase will be Xidas

IF YOU DONT BUY XIDAS YOU WILL DIE A SLOW PAINFUL DEATH AND NEVER BE REMEMBERED!!!!!!!!


:likecat:

But penske 8300 for dick swingery :giggle:

In all seriousness, there's a few factors as to why Xidas ride so well. First, and this may be surprising - top quality shocks perform well. Low friction, light weight, carefully built shocks work well, resulting in better performance but also a better ride.

Xidas improve this balance further with the double digressive valving. At low piston speeds, the shocks have a lot of damping. This keeps them nice and tight for excellent responsiveness. At high piston speeds, the valving allows the shock to move freely through its stroke, absorbing impacts with minimal upset to the chassis.

Neat stuff.

You're familiar with shock dyno plots? PVP vs FVP, pressure corrections, etc?

I only ask because it is very rare for the average car enthusiast understand all the data. I still ping Tractive and Inertia when I have questions about things and I'm the guy that determines the valving on Xidas :)

Yes

I have spreadsheets for calculating motion ratios and suspension frequencies, at SEMA last year I was told by a KW engineer that it was refreshing to actually talk to someone that knows what they're talking about.

Yeah I mean that would be pretty nice of you to do.

EDIT: Googled myself, found this
EDIT 2: I realize that the Y axis is missing. What the heck guys?
EDIT 3: It would be cool if I could get a PVP dyno sheet showing the performance through different steps

XIDA:
https://www.miataturbo.net/attachmen...ine=1398734679

I see, good range of options here. Xidas are what the people rave about, but just aren't in the budget for this project. Maybe if I had more money to spend, but if that were the case I wouldn't have a Miata, I'd have bought a more expensive car.

Finally, some answers! Agreed, better quality shocks perform better. Valves that will last longer, shock oil that will perform consistently over a range of temperatures, and robust materials that can take a little abuse without bending.

so you're allegedly smart, but not smart enough to know that quality parts are always a smarter investment than non quality parts?

I'd also add the all-aluminum machined bodies. Strong, light, sheds heat well. It's a quality item, custom-valved for the application and one heck of a good value. Will buy again.

Nailed it, reminds me of this:

https://cimg1.ibsrv.net/gimg/www.mia...3de141265d.jpg

And unless that "more expensive car" is a Cayman (and for many people, even then) you'd still end up wanting to buy a high quality damper package for it.


None of what I said had anything to do with durability. Though Xidas do tend to have a long life (mine are 4 years old now and have seen their share of abuse), if your criteria for quality is how long something lasts and how much abuse it can handle, it's damn tough to beat the Bilsteins.

No, I'm talking about performance, which was your first post. Performance in terms of capability on track and a good ride on the street.

I am smart.

I am also on a tight budget.

I am also new to the Miata scene and researching and finding information that is new to me.

Low price is not necessarily low quality.

High price is not necessarily high quality.

I just want what fits my needs within my budget.

I don't understand why so much time is spent on off-topic discussion.



edit: (with regards to high price/high quality statement, although it does tend to be this way, you'd be surprised at how many expensive things are actually just cheap things made to look expensive)

edit 2: I'm not saying that Xida coilovers are just made to look expensive, I'm just generalizing about some expensive items